Process for hydrocarbon oil conversion



April 26, 1938. J, Q ALTHER 2,115,606

PROCESS FOR HYDROCARBON OIL CONVERSION Original Filed vApril 17, 1929designed to accomplish the best results.

Patented Apr.`- 2b, 1938 PATENT OFFICE PROCESS FOR HYDROCARBON GILCONVERSION Joseph G. Aimer. chicago, nl., assigner to Universal OilProducts Company, Chicago, Ill., a corporation of Delaware Originalapplication April 17, 1929, Serial No. 355,704. Divided and thisapplication June 27,

1936, Serial No. 87,689

14 Claims.

This is a division of my co-pending application Serial No. 355,704,iiled April 17, 1929, now Patent No. 2,091,261.

This invention relates to improvements in process for hydrocarbon oilconversion, and refers more particularly to improvements designed forthe efficient cracking of hydrocarbon oils to convert and producetherefrom products having higher commercial value.

The utility of the invention as well as many o'b- `iects and advantagesthereof will be brought out in the following description.

The principal object of the invention is to subject hydrocarbon oil tosuch conditions of temperature and pressure as to produce maximum yieldsof lighter gravity products suitable for use as motor fuel with aminimum coke and gas loss.

Another object is to provide for lowering the reflux ratio by making itpossible to convert a greater proportion of `the higher boiling pointhydrocarbons per pass through the unit. This is of particular importancein effecting the capacity and thermal eiliciency of the process.

Another purpose of the invention resides in the employment of means toincrease the decomposition of both the vapors and liquid from thepressure expansion drum under controlled conditions This feature notonly has an effect in increasing the yields of lighter hydrocarbonsobtained from the operation but also in improving their quality,especially for use as a motor fuel, in that they will consist morelargely of higher antiknock compounds.

Briefly, the process of as follows:

The charging stock plus reux will be pumped through a conventionalfurnace having a large heating surface from which the heated oil may thepresent invention is be transferred to a drum. This drum may be unheatedbut lagged against excessive radiation losses. Expansion takes place inthe drum from which vapors may be withdrawn separately, passingpreferably through a vapor heating coil to provide further conversionand into a zone of lower pressure into which residual oil from theexpansion drum may be directed.

From this point on the usual operation takes place, i. e., all thevapors from the flashing still are directed to a dephlegmator where thesufficiently converted fractions are separated from the heavier ends(reflux) by the incoming cold raw oil or other cooling medium, saidreflux being returned to the cracking coil for retreatment.

In order to more clearly understand the invention,`I have shown theaccompanying drawing, which is a diagrammatic view, but not to scale, ofan apparatus suitable for carrying out the invention.

Referring to the drawing and to the operation of the invention, the oilto be treated is directed through line I and branch 2, having valve 3into a heating coil 4, located in a furnace 5.

In heating coil 4 the oil is heated to a temperature within the crackingrange under a suitable pressure. The amount of oil passed through thecoil per unit time, and the size of the apparatus are so correlated thatunder the temperatures and pressures used the degree of crackingobtained in the heating coil is preferably short of that degree ofreaction at which formation oi coke and sludge-like matter occurs, orexceeds a predetermined desired degree.

Chamber I0 may take any desired form and size in relation to thecapacity of the apparatus. It may be unheated and insulated against lossof -heat by radiation and may be maintained at a temperature notsubstantially higher than the temperature of the oil introduced theretofrom heating coil 4 through line 6 and valve 1.

On the other hand, particularly for the -heavier charging stocks anddepending upon the limitations imposed upon the amount of coke andsludge to be formed or contained in the products, it may be desirable tomaintain the materials in chamber l0 at; a' temperature lower than thatreached at the discharge of heating coil 4 to decrease the rate at whichthe reaction proceeds in chamber I0. To this end the oil may be cooledchamber l0 to ladditional heating at elevated tem-fl peratures to effecta controlled degree of sci-called vapor-phase cracking whereby I amenabled to produce lighter valuable distillates having thecharacteristics of motor fuels or gasoline, possessing high anti-knockproperties due to the'presence of controlled proportions of, aromaticand unsaturated hydrocarbons formed by said vapor cracking. g

For this purpose a vapor coil 22 may be positioned in furnace 5 andlocated therein in such let a manner that the combustion gases pass overcoil 22 before passing over coil 4. In this manner and because thecombustion gases passing over coil 22 are at a higher temperature thanwhen they pass over coil 4, a greater degree of radiant heat may beutilized in coil 22 than in coil 4. Coil 22 may be connected to vaporline I9 through branches 23 and 24, respectively, controlled by valves25 and 26. By proper regulation of valves 26, 25, and 26, any desiredamount of vapors separated in chamber I6 may be passed through the vaporheating coil 22. 'I'he vaporous products from line I9, including theheated products supplied thereto from coil 22 pass through line |66 intochamber 54 at any desired point in this zone by regulation of valves 51,preferably entering the lower portion of this zone and comminglingtherein with the liquid products sup-` plied, as will be laterdescribed, from chamber I6 to chamber 54, whereby to supply additionalheat to said liquid products and assist their further vaporization.

The heavier liquid products are withdrawn from chamber I6, preferablyfrom the bottom thereof, through line I having valve 52 and are directedto flash chamber 54 to be subjected therein to ash distillation to anydesired degree. Chamber 54 is provided with a bottomdraw-off 6I, havingvalve 62, whereby liquid or semi-solid products may be removedtherefrom. Solid matters formed in the operation of the process anddeposited in chamber 54 may be removed therefrom through top and bottommanholes in the usual manner.

Raw oil to be treated in the process may be drawn from suitable storagetanks (not shown) through line 46 and pump 44. From'line 43 and bysuitable control of the valves shown, all or a portion of the raw oil tobe treated in the process may be diverted through line 45. having valve46, then to line 41 which connects with the main feed line I, wherebyall or a portion of the charging stock may be fed directly to theheating tubes.

Vapors separated by flash distillation in cham' ber 54 may be removedtherefrom through line 66 having valve 61 to fractionating column 69,wherein they are subjected to controlled condensation by introducinginto dephlegmator 69 suitable cooling medium through line 16 havingvalve 1I; or raw oil to be charged to the process may be diverted fromline 46 through line 12, having valve 13 and introduced to column 69.

Vapors uncondensed in column 69 may be removed therefrom through upperdraw-oil! line 14, having valve 15, and passed to condenser 16, thenceto receiver 11, having usual gas release valve 16 and distillate releasevalve 19. The fractions of the vapors condensed in column 69 may bedischarged from the bottom thereof throughv line 66, in which may beinterposed pump 6I,v

from which they are directed through line 64,

Ahaving valve 65, lconnected with feed line 41,

be desirable to cool the vapors immediately after they are subjected tovapor-phase cracking in coil 22. Suitable lines and valves (not shown)may vbe provided whereby material passing through line 41 may bediverted and injected into line 24'through which the vapors leave coil22. Line 90 controlled by valve 96 is also provided for introducingregulated quantities of the materials passing through line 41 into lineI9 and provision is also made for diverting regulated quantities of oilfrom line I through line 61 and valve 61 into line 6.

A portion of the non-condensable gas from receiver 11 may be returned tovapor line I9 leaving reaction chamber I6 by means of valve 92 in line93. This gas will pass through coil 22 together with the vapors from thereaction chamber or be by-passed through valve 26, depending upon theoperation desired. In any event the uncondensed gas and vapors may beintroduced into chamber 54 at any desired point in this zone and, in theevent the liquid level in chamber 54 is above the point of introduction,the hot gas and vapors will act as a partial pressure agent tofacilitate vaporization in this zone. By controlling the point of entryby means of valves 51, the vapors may enter flash chamber 54 eitherabove or below the liquid level maintained therein. If full advantage ofpartial pressure eifect of these vapors is to be taken, they shouldenter at the lowest point in chamber 54 in order to increasevaporization and facilitate reduction of the percentage of unvaporizedoil.

The valves and pumps shown permit the operator to maintain suitablepressures on the various parts of the apparatus. The flash chamber 54and its connected parts such as dephlegmator 69, condenser 16 andreceiver 11 are preferably maintained at a pressure substantially lowerthan the pressure maintained in chamber I6. Any suitable pressure may bemaintained in vapor cracking 'coil 22 in relation to the pressuremaintained in chamber I6. Heating coil 4 in chamber I6 may be maintainedat substantially the same pressure or the pressure maintained in chamberI6 may be lower than that maintained in the heating coil although stillsubstantially above atmospheric pressure.

As an illustration of the temperatures which may be maintained 'in anoperation carried out in accordance with the invention, the oil may beheated in heating coil 4 to a temperature of, say 920 F.' to 960 F.,said oil entering chamber I6 at a temperature near but relatively lowerthan said temperature. In chamber I6 the oil may be maintained at atemperature of, say 850 to 900 F. The vapors leaving chamber I6 andrecycled gases from receiver 11 may be heated in vapor ,coil 22 to atemperature of approximately 975 to 1100 F. In this illustration apressure of approximately 450 pounds may be maintained on heating coil4.and chamber I6. The pressure may be reduced on flash chamber 54 downto approximately 25 pounds. The vapors leaving chamber I6 may be passedthrough vapor coil 22 under a pressure ofl approximately 100 pounds,

more or less.

It is to be understood that the preferred method of operation is of thelow level type, wherein a minimum quantity of residual oil ismaintainedin the chamber I6. That is, residual oil is withdrawn from chamber I6before it has had sumcient time to form more than 5 per cent of sludgeor coke-like constituents.

I claim as my invention:

1. In-a process wherein hydrocarbon oil charging stock is heated to atemperature sufficient to effect substantial vaporization thereof, itsresulting vaporous and liquid components separated and the vaporssupplied to a separate cracking zone wherein they are subjected totemperature and pressure conditions regulated to effect the productiontherefrom of high yields of good antiknock gasoline, the improvementwhich comprises commingling relatively hotconversion products from saidcracking zone with said liquid components, whereby to effect appreciablefurther vaporization of the latter, removing'the remaining unvaporizedresidue from the system, subjecting the vaporous products includingthose resulting from further vaporization of said liquid components tofractionation for the formation of reflux condensate, subjectingfractionated vapors of the desired end-boiling point to condensation,separating the resulting distillate and uncondensed gases, recoveringthe distillate, and returning a portion of the uncondensed gases to saidcracking zone and therein heating the same to an ofl crackingtemperature together with said vaporous components supplied thereto.

2. In a process wherein hydrocarbon oil charging stock is heated to atemperature sufficient to effect substantial vaporization thereof, itsresulting vaporous and liquid components separated and the vaporssupplied to a separate cracking,

zone wherein they are subjected to temperature and pressure conditionsregulated to effect the Y production therefrom of high yields of goodantiknock gasoline, the improvement which comprises commingling therelatively hot conversion products from said cracking zone with saidliquid components, whereby to effect appreciable i further vaporizationof the latter, removing the remaining unvaporized residue from thesystem, subjecting the vaporous products, including those resulting fromthe further vaporization of said liquid components, to fractionation forthe formation of reflux condensate, returning reflux condensate'formedby said fractionation to further treatment within the system, subjectingfractionated vapors of the desired end-boiling point to condensation,separating the resulting distillate and uncondensed gases, recoveringthe distillate and returning a portion of the uncondensed gases to saidcracking zone and therein heating the same to an oil crackingtemperature together with said vaporous components supplied productsfrom said cracking zone with said liquid components, whereby to effectappreciable further vaporization of the latter, removing the remainingunvaporized residue from the system, subjecting the vaporous products.including those resulting from the further vaporization of said liquidcomponents, to fractionation for the formation of reflux condensate,comminglfng reflux condensate formed by said fractionation with the`charging stock undergoing treatment in the first mentioned heatingstage of the system, subjecting fractionated vapors of the desiredend-boiling point to condensation, separating the resulting distillateand uncondensed gases, recovering the distillate and returning a portionof the uncondensed gases to said cracking zone and therein heating thesame to an oil cracking temperature together with said vaporouscomponents supplied thereto. l e

4. In a process wherein hydrocarbon oil charging stock is heated to atemperature sufficient to effect substantial vaporization thereof, itsresulting vaporous and liquid components separated and the vaporssupplied to a separate cracking zone wherein they are subjected totemperature and pressure conditions regulated to effect the productiontherefrom of high yields of good antiknock gasoline, the improvementwhich comprises commingling relatively hot conversion products from saidcracking zone with said liquid components, whereby to effect appreciablefurther vaporization of the latter, removing the remaining unvaporizedresidue from the system, subjecting the vaporous products, includingthose resulting from the further vaporization of said liquid components,to fractionation for the formation of reflux condensate, subjectingfractionated vapors oi the desired end-boiling point to condensation,separating the resulting distillate and uncondensed gases, recoveringthe distillate, reheating a portion of the uncondensed gases to a highoil-cracking temperature and commingling the same directly and withoutsubstantial cooling thereof with said liquid components from thefirst-named heating stage.

5. In a process wherein hydrocarbon oil charging stock is heated to atemperature sufficient to effect substantial vaporization thereof, itsresulting vaporousand liquid components separated and the vaporssupplied to a separate cracking zone wherein they are subjected totemperature and pressure conditions regulated to effect the productiontherefrom of high yields of good antiknock gasoline, the improvementwhich comprises commingling relatively het conversion products from saidcracking zone with said liquid components whereby to effect appreciablefurther vaporization of the latter, removing the remaining unvaporizedresidue from the system, subjecting the vaporous products, includingthose resulting from the further vaporization of said liquid components,to fractionation for the formation of reflux condensate, eomminglingreflux condensate formed by said fractionation with the charging stockundergoing treatment in the first mentioned heating stage of the system.subjecting fractionated vapors of the desired endboiling point tocondensation, separating the resulting distillate and uncondensed gases,recovering the distillate, reheating a portion of the uncondensed gasesto a high oil-cracking temperature and commingling the same directly andwithout substantial cooling thereof with said liquid components from thefirst-named heating stage.

6. In a process wherein hydrocarbon oil charging stock is subjected tocracking temperature at substantial superatmospherfc pressure, the'resulting vaporous and liquid conversion products separated and thevapors subjected to appreciable additional conversion at increasedtemperature in a separate cracking zone, the improvement which comprisescommingling the additionally cracked vapors, while still at a highertemperature than said liquid products, with the latter in a separatezone, whereby appreciable further vaporization of the liquid products`and appreciable cooling of the additionally cracked vapors isaccomplished, subjecting the vaporous products from said separate zoneto fractionation for the formation of reflux condensate, returningreilux condensate formed by said fractionation to the first mentionedcracking step, subjecting fractionated vapors of the desired end-boilingpoint to condensation, separating the resulting distillate anduncondensed gases, recovering the distillate and returning a portion ofthe uncondensed gases to the second mentioned cracking step and heatingthe same therein to said increased temperature together with thefirst-mentioned vapors. A

7. In a process wherein hydrocarbon oil charging stock is subjected tocracking temperature at substantial superatmospheric pressure, theresulting vaporous and liquid conversion products separated and thevapors subjected to appreciable additional conversion at increasedtemperature in a separate cracking zone, the improvement which comprisescommingling the additionally cracked vapors, while still at a highertemperature than said liquid products, with the latter in a separatevaporizing zone, whereby appreciable further vaporization of the liquidproducts and appreciable cooling of the additionally cracked `vapors isaccomplished, subjecting the vaporous products from said separatevaporizing zonek 'to fractionation for the formation of refluxcondensate, returning reflux condensate formed by said fractionation tothe first mentioned cracking step, subjecting fractionated vapors oi'the desired end-boiling point to condensation, separating the resultingdistillate and uncondensed gases, recovering the distillate, reheating aportion of the uncondensed gases to a high oil-cracking temperature andintroducing `the same directly and without substantial cooling thereofinto said separate vaporizing zone.

8. In a process wherein hydrocarbon oil charging stock is subjected tocracking temperature at substantial superatmospheric pressure, theresulting vaporous and liquid conversion products separated and thevapors subjected to appreciable additional conversion at increasedtemperature in a separate cracking zone, the improvement which comprisescommingling the additionally cracked vapors, while still at a highertemperature than said liquid products, with the latter in a separatezone, whereby appreciable further vaporization of the liquid productsand appreciable cooling of the additionally cracked vapors isaccomplishedl subjecting the vaporous products from said separate ioneto fractionation for the formation of reflux condensate, returning.reflux condensate formed by said fractionation to the rst mentionedcracking step, subjecting fractionated vapors of the desired end-boilingpoint to condensation, separating the resulting distillate anduncondensed gases, recovering the distillate and returning a portion ofthe uncondensed gases to further treatment in the same cracking step towhich said vaporous products are supplied and heating the same therein,to said increased temperature together with the first-mentioned vapors.

9. In a cracking process wherein hydrocarbon oil charging stock issubjected to cracking conditions in a heating coil. the resulting heatedproducts introduced into a separating chamber wherein their vaporous andliquid components separate and from which they are separately removed,the vapors subjected to vapor-phase cracking conditions in a separateheating coil and supplied therefrom to a separate chamber wherein theyare afforded additional conversion time, the improvement which comprisescontacting relatively hot vapors resulting from said vapor-phasecracking with liquid conversion products withdrawn from said separatingchamber, whereby to effect appreciable further vaporization of thelatter, recovering the remaining unvaporized residue, subjecting thevaporous products, including those evolved from the liquid products bysaid further vaporization, to fractionation, supplying reflux condensateformed by said fractionation to the first mentioned cracking operation,subjecting fractionated vapors of the desired end-boiling point tocondensation, recovering and separating the resulting distillate anduncondensed gases, reheating a portion of the latter to a relativelyhigh temperature and introducing the reheated gases directly and Withoutsubstantial cooling thereof into said second mentioned chamber.

10. The improvement as defined in claim 9 further characterized in thatsaid portion of the uncondensed gases is reheated in said separate coilin admixture with the first-named vapors.

11. A conversion process which comprises passing hydrocarbon oil througha heating coil and heating the same therein sufliciently to vaporize asubstantial portion thereof, separting resultant vapors from unvaporizedoil in an enlarged zone, removing the unvaporized oil and introducingthe same into a second enlarged zone, removing vapors from thefirst-named enlarged zone and heating the same to vapor phase crackingtemperature in a second heating coil, subsequently introducing the vaporphase cracked vapors into contact with the unvaporized oil in saidsecond enlarged zone, removing admixed vapors and gases from the secondenlarged zone and subjecting the same to condensation to separate vaporsfrom gases, heating a portion of the separated uncondensed gases to ahigh oilcracking temperature and subsequently introducing the samedirectly and without substantial cooling thereof into contact with theunvaporized oil in said second enlarged zone.

12. The process as defined in claim 1l further characterized in thatsaid portion of the gases f is heated in said second coil in admixturewith the vapors being heated therein to vapor phase crackingtemperature.

13. In a hydrocarbon oil conversion process wherein there is formed amixture of vapors and gases which is fractionated and then subjected tofinal condensation and the incondensible gases separated from the finalcondensate, the method which comprises heating hydrocarbon oil todistillation temperature in a, heating coil and separating the same intovapors and unvaporized ol in a separating chamber, introducing theunvaporized oil into a second chamber maintained under lower pressurethan the first-named chamber, simultaneously heating vapors from thefirstnamed chamber and a portion of said incondensible gases to a highoil-cracking temperature, introducing the thus heated vapors and gasesinto contact with the unvaporized oil in said second chamber, andsupplying admixed vapors and gases from the second chamber to saidfractionating step. v

14. In a hydrocarbon oil conversion process wherein there is formed amixture of vapors and aumcoe gases which is fractionated and thensubjected to inal condensation and the incondensible gases separatedfrom the nal condensate, the method which comprises heating hydrocarbonoil to dising vapors from the first-named chamber and a portion of saidincondensible gases to a high oil-cracking temperature, introducingthe"`thus heated vapors and gases into the lower portion .of the secondchamber` to ow in countercurrent contact with said unvaporized oil, andsupplying admixed vapors and gases from the second chamber to saidfractionating step.

JOSEPH G. ALTHER.

